Typical capacitors comprise a pair of conductive electrodes spaced apart by intervening capacitor dielectric material. As integrated circuitry becomes denser and as individual electronic components such as capacitors get smaller, integrated circuitry fabricators face the challenge of developing capacitor constructions and materials which achieve desired capacitance despite the decreasing size. Example materials under consideration for capacitor dielectric layers include titanates and tantalum pentoxide. These and other capacitor dielectric layer materials can occur in crystalline and in amorphous phases.
It is generally known that the capacitance of dielectric materials such as these can, at least initially, be increased from their as-deposited form by annealing. Such annealing can promote crystallization, re-crystallization or crystal realignment which can facilitate increase in capacitance and reduction in current leakage through the material. However, such annealing can also cause single crystals to be formed in the dielectric layer which in essence extend entirely through the dielectric layer between the layer's opposing surfaces. Annealing or crystal formation to this degree can undesirably have the effect of increasing current leakage. This is primarily due to continuous paths being provided by the continuous grain boundaries for current leakage from one side of the layer to the other. It would be desirable to improve upon these adverse characteristics of capacitor dielectric layer materials.